There's a happy medium imo. Output / value vs hours has diminishing returns over time and such:
- 4 days != 80% output (it's more like 85%)
- 3 days != 60% output (it's more like 70%)
I may be biased though as I run https://4dayweek.io/ - Software Jobs with a better work life / balance.
I wrote about the advantages of a 4 day week (for employers) here:
If we make it a 4 day work week, once it becomes the norm whats to say that people wont want a 3 day work week?